PROs of the assembly: It was easy. The hardest part, to be honest, was stripping all the packing material away.
The bike advertises as arriving 85% assembled. All I had to do was mount the seat, attach the pedals to the crank set, stick the handlebars in their place, mount the front tire, adjust the brakes, tighten the rear reflector and remove the front one (I'll be mounting a light and cell phone holder on the handlebars, the reflector would use up needed space and be redundant).
Call the assembly half an hour at a leisurely pace. Easy and simple. Oh, and that includes transferring my tire pump and water bottle holder from the old Trek to the new bike (which, unlike last year's $80 bike experiment, has mounting points for that stuff). It comes set up for "freewheel" riding. If I wanted it to be a "fixie" I'd have spent a few more minutes flipping the rear tire over.
CONs of the assembly: There were two, one exceedingly minor, one that's annoying and means it will be at least 48 hours before I can ride the bike.
The exceedingly minor con: Critical Cycles advertises their bikes as "Includes all the tools you need for building and maintaining your own bicycle" (Amazon) and "All the tools you need to build and maintain your own bicycle including three metric Allen wrenches and a flat wrench" (the Critical site). But right on the box it mentions you need a Philips screwdriver, and in the accompanying manual it also calls for scissors and a 15mm wrench or crescent wrench. I needed the first two of those other three things, haven't found any place where I'd need the third (the "multi-tool" has several wrench sizes built into it). Just a nitpick: It either comes with all the required tools or it doesn't. If it doesn't, don't say it does.
The annoying con that delays my actual use of the bike: The bike's tubes have Presta valves rather than Schrader valves. If you don't know the difference, the Schrader valve is the valve you know, the one used to put air in "virtually every motor vehicle in the world today," as well as every bike I've ever had until this one. The Presta valve is, in other words, pretty rare. The justification for it seems to be that it's smaller and that the hole for it to poke through the rim doesn't weaken very thin racing-type bike tire rims as much.
It just so happens that my little hand air pump can accommodate a Presta valve. But my tire gauge can't, nor can I air a Presta valve up at a gas station. Which means that I can't even tell how much air is in the tires right now, even if I air them up. So I've ordered a couple of Schrader adapters, which will be here Thursday. THEN I will be able to air up the tires, ride the bike and tell you how that went.